package middle;

import java.util.Arrays;

public class Solution_319 {

    public static void main(String[] args) {
        Solution_319 model = new Solution_319();
        System.out.println(model.bulbSwitch(3));
        System.out.println(model.bulbSwitch(0));
        System.out.println(model.bulbSwitch(1));
        System.out.println(model.bulbSwitch(1000000000));
    }

    public int bulbSwitch(int n) {
        return (int)Math.sqrt(n);
    }
}
